Hydraulic hand pump



B. L. CRIPE HYDRAULIC HAND PUMP April 28, 1964 Filed March 28, 1962 2 Sheets-Sheet 1 INVENTORY LBYJ A/I a! ATTORNEYS April 28, 1964 B. L. CRIPE HYDRAULIC HAND PUMP Filed March 28, 1962 2 Sheets-Sheet 2 ATTORNEYS United States Patent 3,130,675 HYDRAULKI HAND IUW Buddie L. Cripe, Walton, Ind.

Filed Mar. 28, 1962, Ser. No. 183,278 2 Claims. (Cl. 103-37) The present invention relates to a new and novel hydraulic hand pump, and more particularly to a portable pump which is adapted to be readily manually operated and to obtain automatic operation of a driven member at different speeds in accordance with the load on the driven member.

The hydraulic hand pump of the present invention is I especially designed to be portable so that it can be readily moved from place to place as required, the construction accordingly being especially designed to be light-Weight and of a compact nature. With this in mind, the construction of the present invention includes a main body means which is of a very simple and compact construction and within which all of the various fluid passages and valve seats are formed in a most simple and expeditious manner.

One end of a fluid reservoir is connected with and supported by the body means, and a novel handle arrangement is provided which permits ready manual operation of the pump, the handle means being pivotally supported by the body means and also being provided with means for limiting pivotal movement of the handle means in opposite directions. The over-all handle arrangement is such that the pumping pistons may be operated with a minimum of effort on the part of the operator, and the pumping pistons will be reciprocated within certain prescribed limits within the body means.

In many applications, as for example in jacking up cars or operating certain types of metal working tools and the like, it is desired to initially advance a driven member at a rapid rate until it engages the work load, whereupon, it is desired to advance the piston at a slower rate from then on.

The present invention provides a novel arrangement for automatically causing the pump to shift from high speed movement of a driven member to low speed movement thereof. For example, when a hydraulically operated pis ton is the driven member, the piston will initially have a rather fast movement until a load is operable upon the piston, whereupon as the load increases and the pressure builds up in the hand pump of the present invention, the fluid will be by-passed from one of the pumping pistons through a bypass valve back to the reservoir whereupon only one of the pumping pistons becomes operative for driving the driven piston any further. This automatic bypass means eliminates the necessity of stopping the pumping action to open a valve or to operate some other device so as to cause the shift-over to take place from the twopiston actuation of the driven member to the one-piston actuation of the driven member as discussed above.

In addition, in order to release the driven member when desired, a means is provided for venting all of the fluid back into the reservoir, this means taking the form of a relief means including a manually operable relief valve. The relief valve of the present invention is of a particular construction so as to permit the desired adjustment thereof. The relief valve is screw threadedly supported such that it may be manually operated so as to obtain fine adjustment, thereby positioning the relief valve very finely so that the amount of fluid which will pass through the relief means to the reservoir can be accurately controlled.

By providing this type of adjustment, the amount of fluid which passes through the relief means to the reservoir can be either completely cut-off or finely adjusted to provide a slow leakage if such should be desired and on the "ice other hand, it can be completely opened so as to release all the pressure on the driven member, whatever form it may take.

The novel operating mechanism of the present invention includes an elongated handle which extends substantially parallel with the reservoir and includes a hand grip portion at the outer end thereof. This handle mechanism is pivotally supported at the opposite end thereof by means of upwardly extending support means which in turn is pivotally connected with the body means.

This last-mentioned end portion of the handle means is also connected pivotally with the pumping pistons of the apparatus such that pivotal movement of the handle apparatus will result in reciprocation of the pumping pistons.

The handle means includes an integral depending stop lug means which is adapted to engage a portion of the body means for limiting downward movement of the handle means.

In addition, the handle means includes laterally extending stop pin means which is adapted to engage a portion of the support means for the handle means for limiting upward pivotal movement of the handle means. This ensures that the pumping pistons will not be reciprocated an excessive amount in either direction so as to maintain the pumping pistons in proper operative relationship with the body means. Accordingly, the pumping pistons will not be jammed down too far upon their seats which would tend to damage the seating with the body means, and furthermore, the pumping pistons will not be reciprocated upwardly to such an extent that they lose sealing contact with the sealing means provided in the body means.

The pumping pistons of the present invention are of a different diameter so as to provide the aforementioned initial speed and subsequent slower speed as will hereinafter more fully appear, these two pistons reciprocating in a vertical direction so as to minimize any side loads thereon and having the same stroke of movement so as to provide a most compact and efficient arrangement of the pumping pistons.

An object of the present invention is to provide a new and novel hydraulic hand pump which is particularly adapted to be readily portable and accordingly which is light-weight and compact in construction.

Another object of the invention is the provision of a hydraulic hand pump wherein movement of a driven member is initially relatively fast and whereupon a predetermined loading on the driven member will cause the hand pump to automatically by-pass one of the pumping pistons so as to provide slower movement of the driven member after the load thereon reaches a predetermined magnitude.

A still further object of the invention is to provide a hydraulic hand pump which eliminates the necessity of stopping the pumping action to open a valve or operate some other device so as to shift from high speed operation to low speed operation.

Yet a further object of the invention is to provide a hydraulic hand pump including new and novel operating mechanism which permits ready manual manipulation thereof and which effectively limits movement of the operating mechanism in opposite directions.

Still another object of the invention is the provision of a hydraulic hand pump having a relief means including a relief valve which may be readily and accurately manually adjusted to different positions.

Yet a further object of the invention is to provide a hydraulic hand pump which is quite simple and inexpensive in construction and yet which is quite sturdy and reliable in operation.

Other objects and many attendant advantages of the invention will become more apparent when considered in connection with the specification and accompanying drawings, wherein:

FIG. 1 is an elevation of the novel hydraulic hand pump of the present invention shown in solid lines, along with a driven means indicated in phantom lines;

FIG. 2 is a top view of the apparatus shown in FIG. 1;

FIG. 3 is a section partially broken away taken substantially along line 3-3 of FIG. 1 looking in the direction of the arrows.

FIG. 4 is a cross-section partially broken away taken substantially along line 44 of FIG. 3 looking in the direction of the arrows;

FIG. 5 is a cross-section partially broken away taken substantially along line 5-5 of FIG. 3 looking in the direction of the arrows; and

FIG. 6 is a cross-section taken substantially along line 66 of FIG. 3, looking in the direction of the arrows.

Referring now to the drawings wherein like reference characters designate corresponding parts throughout the several views, there is shown in FIGS. 1 and 2 the hydraulic hand pump of the present invention including a main body means indicated generally by reference numeral 1d, a reservoir indicated generally by reference numeral 11, and ancperating mechanism indicated generally by reference numeral 12.

As seen in FIG. 1, a driven member is indicated by phantom line 15 and may take various forms, the driven member being shown as a hydraulic cylinder within which is a suitable hydraulic piston which may be utilized for operating a jack or any other similar mechanism. The hydraulic cylinder 15 is connected with the pump of the present invention by means of a suitable flexible fluid line indicated by phantom line 16 in FIG. 1.

The lefthand portion of the main body means as seen in FIGS. 1 and 2 is provided with a cylindrical recess in the side thereof, this cylindrical recess being indicated by reference numeral 2% in FIGS. 4 and 5. This cylindrical recess receives one end portion of the tubular reservoir member 21, a gasket 22 being inserted between the end of tubular member 21 and the bottom of recess 20. An end cap 24 is provided at the open end of tubular member 21 and serves to close oif this open end, the end cap having a pair of apertured lugs 25 formed at the lower portion for clamping the end cap in position on a supporting surface if such should be desired.

An elongated rod 27 as seen most clearly in FIG. 3 extends through the central portion of the hollow interior of tubular member 21, this rod having the inner end 28 thereof threaded within a suitable threaded opening 29 provided in the main body means 19, the opposite end of rod 27 being threaded and receiving thereon a suitable acorn nut 3d.

Rod 27 extends through a suitable central aperture provided in end cap 24, a gasket 31 being provided for sealing the opening through which the rod extends, the gasket being pressed into position by a washer 32 which in turn engages the acorn nut.

A plug member 33 is threaded within a suitable filling opening provided in the side of the tubular reservoir member 21, it being apparent that the reservoir may be filled through this opening when desired. It is also apparent that the reservoir may be readily disassembled from the main body means when desired simply by removing the acorn nut 3d and then disassembling the parts as well be readily understood.

Referring now particularly to FIGS. 4 and 5 of the drawings, it will be seen that a pair of chambers 35 and 36 are formed within the main body means, these chambers being substantially cylindrical and extending ver tically within the main body means, these chambers receiving snugly therewithin reciprocating pumping pistons 37 and 38 respectively. It will be noted that the lower ends of pumping pistons 37 and 35 are adapted to seat upon shoulders 39 and 443 respectively provided at the bottom of the associated chambers.

Enlarged cavities 42 and 43 are formed within the body means and are in communication with the upper ends of chambers and 36 respectively, these cavities receiving therewithin a plurality of packing members 44 and 45 respectively which fit snugly about the outer surface of the associated pumping pistons to ensure an effective fluid seal therewith.

The upper inner portions of each of cavities 42 and 43 are provided with screw threads 47 and 48 respectively which receive therewithin correspondingly threaded packing nuts 49 and 50, these packing nuts serving to retain the packing members 34 and 45 in position as is clearly apparent in the drawings. The packing nuts may be provided with suitable openings 49' and 50' respectively formed in the upper surfaces thereof for receiving a wrench for readily inserting and removing the packing nuts relative to the body means.

Inlet means provides communication between the reservoir and each of the pumping piston chambers 35 and 36, the inlet means including a first horizontal passage 52 which opens at one end into the reservoir and at the opposite end is in communication with a vertically extending passage 53 which joins a tapered seat 54 upon which a ball check valve 55 rests.

It is apparent that upward movement of piston 37 will suck liquid through passages 52 and 53 to lift the ball 55 off its seat and to allow liquid to flow into chamber 35, whereas upon downward movement of the piston 37, the ball 55 will be seated and the liquid will flow through an outlet means hereinafter described.

The inlet means also includes a passage 57 formed in the body means, one end of passage 57 opening into the reservoir and the other end of passage 57 being in communication with an upwardly directed passage 58 which connects with a tapered seat 5h upon which is seated a ball check valve 60. Ball check valve 60 will also, of course, permit flow of liquid from the reservoir into the piston pumping chamber, but will close so as to prevent the liquid from being forced back into the reservoir.

Outlet means provides communication between each of the piston pumping chambers and some suitable driven member as hereinbefore discussed. The outlet means includes a first horizontal passage 62 which provides communication between chamber 35 and a vertical passage 63 formed in the main body means, passage 63 joining with a tapered seat 64 upon which a ball check valve 65 rests. Ball check valve 65 is disposed at the bottom of a cavity 66 within which is disposed a compression spring 67, the upper end of which engages a pipe plug 68 which is threaded within the threaded upper portion of the recess. It is apparent that adjustment of pipe plug 68 is adapted to adjust the force which spring 67 applies to ball 65, and accordingly, the pressure at which ball check valve 65 opens may be adjusted. It is also evident that ball check valve 65 will permit liquid to fiow from passage 63 to cavity 66, but will prevent reverse flow from the cavity into the passage.

A horizontally extending passage 70 is in communication with cavity 66, passage 70 in turn being in communication with a passage 71 extending forwardly through the body means and in turn providing communication with the interior of a suitable flexible hose connection 16 which as mentioned previously may be connected with any suit able driven member.

The bottom end of passage 63 is in communication with a laterally extending passage 75 which is threaded at the outer end thereof and which receives a screw 76 which is threaded therewithin, a gasket 77 being provided between this groove and the body means to provide a fluid seal.

Passage 75 is in communication with a vertically extending passage 80 which joins with a tapered seat 81 upon which is seated a ball check valve 82. Ball check valve 82 lies at the bottom portion of a cavity 83 provided within the body means. A compression spring 85 is disposed within cavity 83 and is positioned between ball 82 and a pipe plug 86 which is threaded within the threaded upper end of cavity 83. It is apparent that by adjusting the position of pipe plug 86, the pressure applied to ball 82 may be varied for controlling the pressure at which this ball check valve, which is actually a by-pass valve, opens.

A horizontally extending passage 90 has one end thereof in communication with cavity 83, this passage extending toward the lefthand portion of the body means as seen in FIG. 3, and in turn being in communicaton with a horizontally extending passage 91 which extends toward the central portion of the body means and in turn is in communication with a passage 92 which opens into the reservoir.

It is accordingly apparent that by-pass valve 82 is adapted to by-pass liquid from chamber 35 back to the reservoir as will hereinafter be more fully explained.

As seen particularly in FIG. 5, a passage 95 has one end in communication with chamber 36, the opposite end thereof being in communication with a vertically extending passage 96 which joins a tapered seat 97 upon which rests a ball check valve 98 disposed at the bottom of a cavity 90 formed in the body means. It will be noted that passage 70 is in communication with cavity 99 such that liquid pumped by piston 38 will pass through passages 95 and 96 past ball check Valve 98 and thence through the outlet passages 70 and 71 previously discussed.

A compression spring 100 is disposed within cavity 99 and is positioned between ball 98 and a pipe plug 101 which is threaded within the upper threaded end of cavity 99 whereby the pressure on ball 98 may be adjusted to adjust the pressure at which this check valve will open.

Relief means is provided for venting all of the liquid from the driven member back to the reservoir, this relief means including a passage 1% as seen particularly in FIGS. 3 and 6 which is in communication with recess 99 and accordingly, is in communication with the outlet of the hydraulic pump.

Passages 105 is adapted to be in communication with passage 106 which in turn as seen in FIG. 3 is in communication with passage 107 which is in communication with the passage 92 previously described, whereby communication is provided back to the reservoir.

A manually operable relief valve is provided for controlling the degree of communication between passages 105 and 106. For this purpose, a seat 110 is provided in the body means and the relief valve is adapted to seat on this portion.

A recess 111 is provided in the body means which receives an O-ring seal 112 formed of rubber or suitable material, and a steel ring 113. A packing nut 114 is threaded within the threaded outer end of recess 111, the packing nut having a threaded central bore therewithin. A manually operable valve indicated generally by reference numeral 115 is provided with a threaded shank 1 16 which is threaded within the threaded internal bore of the packing nut,-the inner end of the shank being provided with a tapered end portion 117 which is adapted to seat on the seat portion 1110 within the body means. The outer end 118 of member 115 comprises a disc-like member with indentations in the outer edge thereof so that it can be readily manually grasped and turned as desired, it being apparent that the screw threaded mount ing for this valve member permits it to be readily adjusted so as to open or close the communication between passages 105 and 106 to any desired degree.

A support means for pivotally supporting the operating mechanism of the present invention includes a first leg portion 120 and a second leg portion 121 as seen most clearly in FIGS. 2 and 3. The lower portion of the main body means includes a first pair of laterally extending ears 122 and 123 and a second pair of laterally extending ears 124 and 125. The lower end of leg 120 is received between ears 122 and 123, and the lower end of leg 121 is received between ears 124 and 125.

The two legs and 121 are supported by the ears by means of a mounting pin 128 which extends through suitable aligned openings in the ears 122-125, and the legs 120 and .121, the pin receiving suitable means such as cotter pins 129 and 130 through suitable openings formed in the opposite ends thereof for retaining the mounting pin in operative position as shown.

The operating mechanism comprises a handle including an elongated cylindrical shank portion 132 as seen most clearly in FIGS. 1 and 2 upon the outer end of which is mounted a hand grip portion 133 formed of a suitable material such as rubber and the like such that it is adapted to be held in the hand. The opposite end of member 132 is connected with a member 135 which may be termed a fulcrum member, this fulcrum member including a depending stop lug portion 136 which is adapted to engage an upper surface of the main body means for limiting downward pivotal movement of the handle.

The under surface of member 135 is cut away at 140 as indicated by the dotted lines in FIGS. 1 and 2 to define -a pair of longitudinally extending ribs .141 and 142. A first connecting link 143 has the upper portion thereof pivotally connected with rib 141 and the lower end thereof pivotally connected with the upper end of a pumping piston 37 as seen most clearly in FIG. 4. It will be noted that the upper end of the pumping piston 37 is provided with .a pair of flats 1'44 thereon for receiving the connecting link.

A second connecting link 145 is provided, the upper end of this link being pivotally connected to rib 142 and the lower end of this link being pivotally connected to the upper end of pumping piston 38 as seen most clearly in FIG. 5, pumping piston 38 also being provided with a pair of flats 146 thereon for receiving the lower end of the connecting link.

As seen in FIGS. 1 and 2, the end portion of member 1135 is pivotally supported by the leg members 120 and I121 by means of a mounting pin 150 which extends through suitable aligned openings formed in leg members 120 and 121 and the rib members 141 and 142 of member 135.

The pin may be retained in position by a suitable means such as cotter pins and the like.

It will be observed from the foregoing description that the handle is pivotally supported by the leg portions 120 and 121 and that oscillations of the handle member will cause vertical reciprocation of the pumping pistons 37 and 38 through the connecting links .143 and 145. Stop lug 136 will limit downward movement of the handle means.

In order to limit upward movement of the handle means a pair of laterally extending stop pins and 156 are mounted in rib portions 141 and 142, and extend laterally outwardly thereof as seen most clearly in FIG. 2.

It will be apparent that upon upward pivotal movement of the handle means, stop pins 155 and 156 will travel in an arc about the pivot axis of mounting pin 150 and will engage arms 120 and 121 whereupon further pivotal movement of the handle about the arms will be prevented. This effectively prevents upward movement of the handle means and prevents excessive movement in an upward direction of the pumping pistons as will be apparent.

In operation, the pressure of the various springs operating on the ball check valve may be initially adjusted with particular care being taken to adjust the pressure on ball check valve '82 which determines the pressure at which liquid will be by-passed from pumping piston 37 back to the reservoir.

The manually operated relief valve 115 will also be initially adjusted to either completely close off the flow of liquid back to the reservoir or this valve may be selectively opened a desired degree to enable a certain amount of fluid to bleed back to the reservoir if such should be desirable. Initial pumping action of the handle will, of course, as aforedescribed, produce vertical reciprocation of the pumping pistons with such reciprocation being limited in opposite directions by the limit stop means as set forth.

Vertical reciprocation of the pumping pistons will initially produce liquid flow from both pumping pistons through the ball check valves 65 and 98 and thence through the outlet means to the driven mechanism. Initial movement of the driven mechanism will accordingly be relatively fast since both pumping pistons are supplying liquid thereto. When the load on the driven member reaches a certain magnitude such that the pressure builds up in the system to a certain level, ball check valve 65 will remain closed and ball check valve 82 will open to by-pass liquid from the pumping piston 37 back to the reservoir. When this happens, subsequent pumping of the hand pump will cause only the pumping piston 38 to be eifective to force additional liquid to the driven means such that subsequent movement of the driven means will be relatively slow.

When it is desired to release the driven means completely, the relief valve 115 may be backed off to provide free communication between passages 105 and 106, whereby the liquid from the driven means will be vented back to the reservoir.

It is apparent from the foregoing that there is provided a new and novel hydraulic hand pump which is readily portable and which is of a very light-weight and compact construction. Movement of a driven means by the hand pump of the present invention will be initially rapid and when the load reaches a certain magnitude, one of the pumping pistons will be automatically bypassed back to the reservoir such that only one of the pistons subsequently effectively produces movement of the driven means and accordingly any further movement of the driven means will be slower as long as the load remains at a certain level.

The arrangement of the present invention completely eliminates the necessity of stopping operation of the hand pump to open a valve or to operate any other device for switching from fast operation to slow operation since the device is completely automatic in this respect.

The operating mechanism of the present invention permits ready manual manipulation, and limit stop means is provided for effectively limiting movement of the operating mechanism in opposite directions so as to prevent excessive travel of the pumping pistons. The relief valve means of the present invention can be readily and accurately manually adjusted so as to open or close the relief valve to any desired degree. The hydraulic hand pump of the present invention is quite simple and inexpensive in construction, and yet is quite sturdy and reliable in operation.

As this invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, and since the scope of the invention is defined by the appended claims, all changes that fall within the metes and bounds of the claims or that form their functional as well as conjointly cooperative equivalents are therefore intended to be embraced by those claims.

I claim:

1. A hydraulic hand pump including a body means, a fluid reservoir connected with said body means, a pair of pumping pistons reciprocably mounted within a pair of chambers in said body means, inlet means providing fluid communication between said reservoir and each of said chambers and including one-way valve means for allowing fluid flow in one direction and preventing fluid flow in the opposite direction, outlet means in fluid communication with each of said chambers and including one-way valve means permitting fluid flow in one direction and preventing fluid flow in the opposite direction, by-pass means including a normally closed valve adapted to open at a predetermined pressure and providing communication between one of said chambers and said reservoir, and relief means providing communication between said outlet means and said reservoir, each of said chambers including seat means at the lower portions of the chambers against which the associated pistons are adapted to seat upon downward movement of said handle means, a pivotally supported, manually operable handle means, said handle means being connected to each of said pistons, and depending stop means formed on said handle means and adapted to engage a portion of said body means for limiting downward movement of said handle means, support means pivotally connected with and extending upwardly from said body means, one end portion of said handle means being pivotally connected with an upper portion of said support means, and laterally extending stop pin means extending from said handle means and adapted to engage a portion of said support means upon rotation of said handle means about its pivotal connection with said support means whereby said stop pin means serves to limit upward movement of said handle means.

2. A hydraulic hand pump including a body means, a fluid reservoir connected with said body means, a first pumping piston reciprocably mounted within a first cham her in said body means, a second pumping piston reciprocably mounted Within a second chamber in said body means, said first piston and said first chamber being of larger dimension than said second piston and said second chamber, inlet means providing fluid communication between said reservoir and each of said chambers and including one-way valve means for allowing fluid flow in one direction and preventing fluid flow in the opposite direction, outlet means in fluid communication with each of said chambers and including one-way valve means permitting fluid flow in one direction, and preventing fluid flow in the opposite direction, by-pass means including a normally closed valve adapted to open at a predetermined pressure and providing communication between said first chamber and said reservoir, and relief means including a manually operable valve which is threadedly supported by said body means for permitting fine adjustment thereof for controlling the amount of fluid passing through said relief means, and a pivotally supported manually operable handle means, said handle means being connected to each of said pistons, and limit stop means to limit pivotal movement of said handle means in opposite directions, said limit stop means including a depending stop lug adapted to engage a portion of said body means and said handle means including laterally projecting stop pin means at the outer end thereof, said outer end of the handle means being supported by upwardly extending support means, said limit stop means being adapted to engage said support means upon pivotal movement of said handle means in an upward direction.

References Cited in the file of this patent UNITED STATES PATENTS 2,044,857 Pfauser June 23, 1936 2,250,551 Pfauser July 29, 1941 2,255,984 Pfauser Sept. 16, 1941 2,277,256 Pfauser Mar. 24, 1942 2,442,058 Page May 25, 1948 2,495,319 Ferris et a1. Jan. 24, 1950 2,610,025 Mueller Sept. 9, 1952 2,696,850 Peterson Dec. 14, 1954 2,815,646 Swanson Dec. 10, 1957 

1. A HYDRAULIC HAND PUMP INCLUDING A BODY MEANS, A FLUID RESERVOIR CONNECTED WITH SAID BODY MEANS, A PAIR OF PUMPING PISTONS RECIPROCABLY MOUNTED WITHIN A PAIR OF CHAMBERS IN SAID BODY MEANS, INLET MEANS PROVIDING FLUID COMMUNICATION BETWEEN SAID RESERVIOR AND EACH OF SAID CHAMBERS AND INCLUDING ONE-WAY VALVE MEANS FOR ALLOWING FLUID FLOW IN ONE DIRECTION AND PREVENTING FLUID FLOW IN THE OPPOSITE DIRECTION, OUTLET MEANS IN FLUID COMMUNICATION WITH EACH OF SAID CHAMBERS AND INCLUDING ONE-WAY VALVE MEANS PERMITTING FLUID FLOW IN ONE DIRECTION AND PREVENTING FLUID FLOW IN THE OPPOSITE DIRECTION, BY-PASS MEANS INCLUDING A NORMALLY CLOSED VALVE ADAPTED TO OPEN AT A PREDETERMINED PRESSURE AND PROVIDING COMMUNICATION BETWEEN ONE OF SAID CHAMBERS AND SAID RESERVOIR, AND RELIEF MEANS PROVIDING COMMUNICATION BETWEEN SAID OUTLET MEANS AND SAID RESERVOIR, EACH OF SAID CHAMBERS INCLUDING SEAT MEANS AT THE LOWER PORTIONS OF THE CHAMBERS AGAINST WHICH THE ASSOCIATED PISTONS ARE ADAPTED TO SEAT UPON DOWNWARD MOVEMENT OF SAID HANDLE MEANS, A PIVOTALLY SUPPORTED, MANUALLY OPERABLE HANDLE MEANS, SAID HANDLE MEANS BEING CONNECTED TO EACH OF SAID PISTONS, AND DEPENDING STOP MEANS FORMED ON SAID HANDLE MEANS AND ADAPTED TO ENGAGE A PORTION OF SAID BODY MEANS FOR LIMITING DOWNWARD MOVEMENT OF SAID HANDLE MEANS, SUPPORT MEANS PIVOTALLY CONNECTED WITH AND EXTENDING UPWARDLY FROM SAID BODY MEANS, ONE END PORTION OF SAID HANDLE MEANS BEING PIVOTALLY CONNECTED WITH AN UPPER PORTION OF SAID SUPPORT MEANS, AND LATERALLY EXTENDING STOP PIN MEANS EXTENDING FROM SAID HANDLE MEANS AND ADAPTED TO ENGAGE A PORTION OF SAID SUPPORT MEANS UPON ROTATION OF SAID HANDLE MEANS ABOUT ITS PIVOTAL CONNECTION WITH SAID SUPPORT MEANS WHEREBY SAID STOP PIN MEANS SERVES TO LIMIT UPWARD MOVEMENT OF SAID HANDLE MEANS. 